Study On The Structure And Material Design Of Bridge Paving Asphalt Concrete At Cold Aera

As the protective part of the bridge, the bridge deck pavement can greatly ease the traffic impact of the bridge deck and meet the requirements of smooth driving. The quality and durability of the pavement make a direct impact on traffic safety, comfort and bridges durability and investment returns. In cold areas, due to low winter temperatures, it is more prone to emerge hypothermia cracks in deck pavement, rain and snow is more easily penetrated to the bridge deck so that the entire bridge structure obtains serious harm. Moreover, due to the low winter temperatures, construction workability could be a greater challenge, we need to add warm mix agent to reduce the mixing and compaction temperatures to ensure the performance of asphalt concrete to meet the requirements. Considering the cold area climate characteristics, this paper dose deep research on structure and material design of the bridge deck, the main content and conclusions are as follows:1. For the deck pavement material requirements and characteristics in cold area, and verified by laboratory tests, this paper proposed the selection to use "4cm SBS modified asphalt concrete(AC-13) + 5cm medium-grained asphalt concrete(AC-16) + waterproof adhesive layer" as a bridge structure pavement, and made a systematic summary about waterproof bonding layer. When the pavement is constructed in autumn and winter low temperature environment, this paper make a suggestion that add DAT-H5 warm mix agent to asphalt concrete, in order to reduce the adverse effects of low-temperature environment to pavement construction.2. Design the mix proportion for the AC-13 and AC-16 asphalt concrete according to layer performance requirements, and determine the respective optimum asphalt ratio, and do the test for each structural layer of asphalt concrete on road performance by laboratory testing, test results show that the two graded road performance requirements can be met.3. After the addition of 10% of DAT-H5 warm mix agent, when the mixing temperature changed from 100 ℃ to 130 ℃, warm mix modified bitumen viscosity reduced significantly; when mixing the temperature reaches and exceeds 130 ℃, the viscosity of the mixing DAT-H5 SBS modified asphalt and warm mix agent which is not mixed with modified bitumen is basically the same, which indicates that between 100 ℃ ~ 130 ℃, DAT-H5 on asphalt viscosity has a significant role.4. The variable temperature Marshall Compaction Test shows that the content of 10% dropped of about 25 ℃ for asphalt mixing temperature.5. Make the test of the adding DAT-H5 asphalt concrete on pavement performance, the test results showed: DAT-H5 can improve the performance on high-temperature rutting resistance and resistance to water damage asphalt mixture. As for the ability of the low temperature cracking resistance, there is tiny reduction, but still meet road performance specifications.6. Considering Changchun area for climate characteristics, combined with the results of the above study, this paper presented construction plan for bridge deck, it is meaningful to provide a reference value for practical engineering in the future.